Properties of ultrathin layers of Rh, Au, Mo and K deposited on TiO2(110) surface were examined in function of annealing and in the reactions with different gases. The most important results are the followings: (1) by exploitation of the strong metal support interaction (SMSI) between Pt and TiO2, a method was worked out for pit-formation driven by the Pt crystallites produced previously on TiO2(110); (2) it was shown by STM that the growing of 3D Mo particles begins first in the oxygen deficient regions of the support; (3) according to the I-V measurements, the Mo crystallites formed at 900 K in UHV exhibit insulator behaviour what suggests (by taking into account also the XPS measurements) that the Mo particles become encapsulated by a thin TiOx layer; (4) in the case of Rh a similar decoration of the supported metal particles was also demonstrated by LEIS; (5) it was shown that the deposition of Au on the support reduced by low energy Ar+ ion bombardment or by pre-exposing the surface to K results in a significantly higher dispersity of Au; (6) the gold particles of 3-4 nm supported on TiO2(110) exhibit high activity in the low temperature CO oxidation (PROX) between 350 K and 500 K, at the same time they exhibit a pronounced agglomeration above 400 K; (7) a method was suggested to transform of the Mo nanoparticles supported on TiO2(110) into Mo-carbide particles in the decomposition of C2H4 (5 x 10-6 mbar) at 850 K accompanied by low energy (1 keV) Ar+ bombardement.